Mélange de bandes au début de la couche 2s–1d

Abstract

A formulation in the strong coupling collective model framework with several valence nucleons is presented for odd mass nuclei. The position of the single nucleon in the shell is restricted only by the exclusion principle and a simple and correct treatment of the J2 term is proposed. Appreciable differences occur in the 2s–1d shell with respect to the previous treatments, which neglect the one-particle–two holes configurations. As examples, the 25Na, 27Mg, and 23Ne nuclei are discussed. The level schemes predicted by the model are in good agreement with the experimental data and compare favorably to recent shell model results.